What is USB Type C and Why it Matters?

Many designers still don’t know what’s coming with the next generation of USB connection. That’s why it’s time to look at the basics.

By John Blyler, Editorial Director, “IOT Embedded Systems”

This brief tutorial of the basics on the next generation USB Type C connector will provide a background for further design-oriented pieces on this new interface.

What is it?

The USB Type-C connector is the next generation of USB interface. This recently completed specification makes the new connector easier to use, supports much faster data rates, and delivers higher-power charging. Specifically, the USB Type-C specification calls for data transfer rates of up to 40Gbps (80 times faster than a USB2.0 or Lightning connection) in the new miniature “Type-C” connector which measures just 8.55mm by 2.75mm.

Why is it needed?

The existing USB plug is clunky in that it must be inserted the right way. Further, the data rate isn’t always as fast as we’d like, and the charging function can be frustratingly slow when used to power larger batteries, like those used in many smartphones and tablets. USB Type-C provides a flippable plug, increased speed, and new power delivery (PD) capabilities (see below).

Figure 1. The Type-C connector is smaller and flippable.

What is the growth potential?

The USB Implementers Forum predicts there will be 2.1 billion USB 3.0 and 3.1 (formerly known as SuperSpeed USB and SuperSpeed Plus USB) enabled devices in 2016. That predictions is up 207% from 2014 shipments. According to a recent report from Strategy Analytics, 12% of mobile handsets will feature Type-C connectors by 2016. The first wave of Type C storage devices has already hit the market. Apple’s latest MacBook includes Type C data port. Google includes a Type C interface in it’s latest Chromebook. Several other vendors are incorporation Type C ports including Samsung, Seagate (STX), Toshiba and Western Digital (WDC), LaCie, Scandisk and others.

How is the relationship between USB Type-C and the 3.1 format?

The Type-C connector supports the new SuperSpeed USB 3.1 format, which offers data-transfer rates as high as 10 Gbps, or roughly double the speed of current USB 3.0 versions. It’s still backward compatible with all the USB 2.0 formats (LS, FS, and HS), so even legacy systems will be able to take advantage of the new connector when it’s designed into dongles.

What new applications are possible?

The higher speed gives USB the potential to replace video cables, like DisplayPort and HDMI, which require a separate power cable. The Type-C connector can do both – transfer data fast enough to support a 4K monitor (or an array of monitors), while also delivering power. This has the potential to really boost USB, since it opens up a new set of applications in entertainment and video.

The Type-C connector also supports a new level of charging capability, referred to as USB Power Delivery or USB PD. The PD format runs at up to 100 W, which is suitable for use with 5, 12, and 20 V systems. That’s a big step up from the traditional USB Battery Charger or BC spec, which presents limitations when charging systems with larger batteries, or trying to power a hub or display.

How will it fit into the evolving IoT space?

The Type-C interface will play a big role in mobile and wearable devices. Applications for Type-C implementation include ultra-thin laptops, tablets, mobile devices, solid state disks and wearable computing devices.

–> Next time will look at engineering challenges posted by the Type-C interface including controller and baseband power delivery design issues.